Our little guy (4.5 weeks old) used to sleep 4-5 hour stretches. He went to bed at 10. Then woke up at 3 to eat and was up for the day around 6 or 7.
The last three nights, he's been up every 2-3 hours. How do I know if he's actually hungry or just needs soothed back to sleep?
Re: How to know when to use a pacifier
I do the same. When Lo cries in the middle of the night I give him his paci a few times/several minutes. Many times he will go back to sleep but he is really hungry his fussing won't stop or will turn into full on crying. I joke that his paci is his snooze button.
ETA: you can try gently pulling the paci out of your LO's mouth after putting it in. This "reverse psych" method, as mentioned in "Happiest Baby on the Block," can teach baby to suck harder on the paci to keep it in. If LO still spits it out, it's a sign he/she doesn't want it. I use the paci during daytime moments when I need a boob break or to keep her content in public spaces outside the home.
Go with your gut...every baby is different